1. Field of the Invention
The present invention is directed to a method of supporting a roof, particularly a roof of an underground excavation such as a mine.
The invention is also directed to a system for carrying out the method, i.e. to apparatus for this purpose.
2. The Prior Art
Particularly in the field of underground excavations, for example in the construction of mining galleries, tunnels and the like, it is usually necessary to support the roof of the excavation against caving in. Various approaches for effecting such support are known from the prior art. For example it is known in coal mining particularly to use the so-called "room and pillar system" in which roof bolting is used, i.e. steel rods or bars which penetrate the rock layers and hold them together to prevent collapse. It is also known to provide various types of supporting structures of wood and/or steel in which rigid or slightly yieldable supporting elements are used to support the roof from below against collapse.
The problem with this latter type of approach, to which the present invention is also directed, is that the prior-art proposals are all relatively complicated and expensive and are difficult to erect and to remove. The elements involved are relatively expensive and of considerable weight so that they are difficult to handle.